46,(10-4) choose two:
Examine the data in the CUST_NAME column of the CUSTOMERS table.
- CUST_NAME
- Lex De Haan
- Renske Ladwig
- Jose Manuel Urman
- Jason Mallin
- You want to extract only those customer names that have three names and display the * symbol in
- place of the first name as follows:
- CUST_NAME
- *** De Haan
- **** Manuel Urman
- Which two queries give the required output?
- A) SELECT LPAD(SUBSTR(cust_name,INSTR(cust_name,'')),LENGTH(cust_name),'*')"CUST NAME" FROM customers
- WHERE INSTR(cust_name, ' ',1,2)<>0;
- B) SELECT LPAD(SUBSTR(cust_name,INSTR(cust_name,'')),LENGTH(cust_name)- INSTR(cust_name,' '),'*')"CUST NAME"
- FROM customers
- WHERE INSTR(cust_name, ' ',1,2)<>0 ;
- C) SELECT LPAD(SUBSTR(cust_name,INSTR(cust_name,'')),LENGTH(cust_name),'*')"CUST NAME"
- FROM customers
- WHERE INSTR(cust_name, ' ',-1,2)<>0;
- D) SELECT LPAD(SUBSTR(cust_name,INSTR(cust_name,'')),LENGTH(cust_name)- INSTR(cust_name,' '),'*')"CUST NAME"
- FROM customers
- WHERE INSTR(cust_name, ' ',-1,-2)<>0;
- Answer:AC
(解析: 题意是: 您希望只提取具有三个名称的那些客户名称, 并显示 * 符号来代替名称如下注意条件的用法 INSTR(cust_name, '',1,2)<>00, 意思是从名字中找空格, 从第一个开始, 查看第二个空格的位置, 如果有, 说明名字里面就有三个名称, 否则只有两个名称. 同时 INSTR(cust_name,' ',-1,-2), 从倒数第一个空格开始, 不能再用 - 2 了, 要用正数)
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